Key Idea: Topic 5.3 is HL-only and focuses on lean production and related quality approaches. Students are expected to explain how lean methods reduce waste, but also evaluate the risks, culture change and implementation problems that come with them.
⏰ Just-in-time: **JIT —** stock arrives only when needed. **Low storage cost**. **Low waste**. **Risk —** vulnerable if suppliers fail.
📦 Just-in-case: **JIC —** extra stock held as a buffer. **Safer against disruption**. **Higher storage cost**. **Risk —** more cash tied up and more waste.
🔄 Kaizen: **Kaizen —** continuous improvement through small changes. **Involves all workers**. **Builds a culture of improvement**.
♻️ Cradle to cradle: **Cradle to cradle —** products designed for reuse, recycling or safe return to nature. **Links lean to sustainability**. **Supports circular thinking**.
HL exam tip: Do not present lean as automatically good. Examiners reward answers that explain both efficiency gains and the risks of low buffers, culture change or supplier dependence.
A strong HL answer often links lean tools together. For example, JIT works better when supported by Kaizen, quality assurance and strong supplier relationships.
Example: A strong answer: JIT may reduce storage costs and waste because the business holds very little stock. However, if suppliers are unreliable, production may stop completely, so the suitability of JIT depends on the strength of the supply chain.
Important: Common triggers: define lean production, explain JIT or JIC, analyse Kaizen, discuss benefits and risks of lean, explain cradle to cradle, or evaluate whether a lean approach suits the business.
- Identify the lean method or concept
- Explain how it reduces waste or improves value
- Apply it to the business in the case
- Add at least one implementation challenge
- Link to cost, quality, speed or supply reliability
- For HL, judge whether the business context makes the method realistic